1. Field of the Invention
The invention relates to a method for program-controlled testing and cleaning of endoscopes having a head pan with an attached insertion tube and a pressure test attachment, and to a cleaning apparatus for carrying out testing and cleaning.
2. Description of the Related Art
Endoscopes are used for examining the stomach or intestine and have a head part made of strong material, usually plastic, with an ocular and, usually, one or more attachments and buttons for triggering certain functions of the endoscope, as well as a flexible insertion tube which is attached to the head part and contains, protected by a tubular plastic sheath, a glass fibre bundle which connects a lens, arranged at the distal end, to the ocular, and a further light guide serving for illumination, and channels through which liquid can be drawn off by suction, water or air can be introduced and instruments can be inserted, for example for the removal of tissue samples.
A supply part is usually connected to the head via a supply tube which likewise contains, protected by a plastic sheath, a number of channels which can be connected to the channels in the insertion tube, on which supply part the said channels and the light guide serving for illumination open into attachments for the supply of water, air and light and for the removal of liquid by suction. Head part, insertion tube, supply tube and supply part are surrounded by an envelope, which consists of the housings of the head part and supply part and the sheaths of the insertion tube and supply tube and which encloses a continuous inner space containing both the channels and light guide mentioned as well as the delicate ocular. Also arranged on the supply part is a pressure test attachment which forms a connection to the inside of the endoscope.
The cleaning of endoscopes, which must be carried out very thoroughly for reasons of hygiene and must include disinfecting, is extremely involved and usually comprises a number of cleaning stages in which at least the insertion tube is exposed to a cleaning liquid under pressure. In a known method of the generic type (CH-A-675 064) the head part of the endoscope is therefore protected by a foam-filled housing, into the inside of which compressed air is fed. By this means, cleaning liquid cannot penetrate into the endoscope at the head part. However, if the insertion tube has a leak, and it is mainly the lower end thereof which is particularly susceptible to leaks, cleaning liquid can nevertheless penetrate into the inside of the endoscope and damage the ocular of the expensive instrument. One further disadvantage is that the head part is not cleaned.
It is also known to pump the endoscope up, using a hand pump, via the pressure test attachment prior to cleaning and in this way to detect any leaks. However, this method is not very reliable, mainly because very small leaks are rarely detectable, and affords no certainty against leaks appearing or increasing in size during cleaning, which can easily happen, particularly since the endoscope usually needs to be treated with cleaning liquid at a relatively high temperature. In addition, the testing in this case is a separate procedure from the cleaning and is relatively time-consuming.
A proven cleaning apparatus of the generic type, whose use nevertheless necessitates a leakproofness test prior to cleaning, is known from the brochure "Wasch- und Desinfektionsautomat fur Endoskope SME 2000" (Automatic washing and disinfection apparatus for endoscopes SME 2000) from the company Belimed AG, 5608 Stetten, Switzerland.